Cast acrylic sheet
PMMA - Poly(methyl methacrylate)
Cast acrylic is a high quality, versatile, clear plastic sheet material offering high levels of strength and clarity while being easy to work with.
Cast acrylic sheet is commonly referred to as Perpex® and Plexiglas® both of which are in fact manufacturer brand names.
Cast acrylic is manufactured by pouring monomer between two sheets of high quality glass and polymerised in batches in a carefully controlled manufacturing process.
Key features:
• Excellent thickness tolerance
• Optical clarity
• High gloss surface on both sides
• Hard wearing
• Weather resistant
• Easy to bend and shape
• Economical
• Suitable for vacuum forming
Typical applications:
• Point of sale
• Retail display
• Models
• Display cases
• Glazing
Working with cast acrylic sheet:
Cutting
We cut extruded acrylic panels to size using a circular saw and a CNC router. But acrylic sheet can also be cut with hand tools. Most hand tools designed for use for wood or soft metal can be used on acrylic. Circular saws, band saws and jigsaws and are all suitable but for small jobs a fine-toothed hacksaw is recommended. Ensure the material is fixed securely and use light controlled pressure to achieve a good finish.
If cutting large amounts of material using a powered saw a tungsten carbide tipped blade would be a sensible investment.
Laser cutting
Laser cutting machines cut acrylic by melting, burning or vaporizing the material. Laser cutting is exceptionably accurate and capable of cutting incredibly intricate designs from a CAD file. The laser cutting process leaves a nice smooth edge so further edge finishing is not necessary.
Edge finishing
When acrylic sheet is cut, the saw blade leaves an unfinished matte finish to the surface of the edges. This can be polished out to crystal clear, high quality finish by either diamond or flame polishing.
Diamond polishing
A diamond edge-polishing machine polishes the edge of the acrylic by running a rotating, diamond tipped wheel along the edge of the material. Diamond polishing leaves a clean and crisp edge. Curved edges cannot be diamond polished.
Flame polishing
Acrylic edges can also be flame polished by running a blowtorch type gar-air flame along the edge. Flame polishing can be used to polish a curved edge when diamond polishing cannot.
Drilling holes in cast acrylic
Standard wood working drill bits are suitable for drilling holes in acrylic. Be sure to use another piece of material (scrap wood or acrylic is perfect) underneath the panel to act as a backstop. This will ensure the drilling will not blowout the panel as the drill exits the material.
Do not under any circumstances use a centre punch on any acrylic panel, its very likely to damage It’s a good idea to start by drilling a small pilot hole to help locate the drill.
Be patient and drill at a steady speed and pause regularly to remove any swarf collecting around the drill, not doing so is likely to cause over heating and in turn will damage the hole.
When approaching the other side of the panel, continue to drill through it and into the backstop to ensure the exit hole does not splinter.
Cleaning
Start by blowing and brushing any loose dirt and dust from the polycarbonate sheet.
With a mild solution of lukewarm water and a drop of standard washing up liquid use a soft cloth to wipe clean any stubborn dirt and grime.
Gently rinse with clean water before dabbing dry with a mircofibre cloth to ensure water spots do not develop.
Polishing scratches
Specialist acrylic polish can be used to polish out fine scratches, however T-cut car polish achieves great results too.